1. Field
The present disclosure relates generally to aircraft and icing conditions and, in particular, to reducing icing conditions for aircraft. Still more particularly, the present disclosure relates to a method and apparatus for an anti-icing system for aircraft.
2. Background
In aviation, icing on an aircraft may occur when atmospheric conditions lead to the formation of ice on the surfaces of the aircraft. In some cases, the formation of ice also may occur within the engine. Ice forming on the surfaces of the aircraft, on inlets of an engine, and on other locations is undesirable and potentially unsafe for operating the aircraft. When these conditions occur, the formation of ice may reduce the performance of the aircraft in an undesired manner.
Icing conditions may occur when drops of supercooled liquid water are present. In these illustrative examples, water is considered to be supercooled when the water is cooled below the stated freezing point for water but is still in a liquid form. Icing conditions may be characterized by the size of the drops, the liquid water content, air temperature, and other parameters. These parameters may affect the rate and extent at which ice forms on an aircraft.
When icing occurs, the aircraft may not operate as desired. For example, ice on the wing of an aircraft may cause the aircraft to perform undesirably at a higher angle of attack and have an increased drag or reduced maximum achievable coefficient of lift. This situation may reduce fuel efficiency for the aircraft or reduce the level flight stalling speed.
Aircraft may have mechanisms to prevent icing, remove ice, or some combination thereof to handle these icing conditions. For example, aircraft may include ice protection systems that detect icing on the aircraft, prevent ice from forming on the surface of the aircraft, remove ice from the surface of the aircraft, or some combination thereof. These icing protection systems may be referred to as anti-icing systems. Ice may be prevented from forming on the surface of the aircraft using bleed air, infrared heating, and other suitable mechanisms.
In some cases, however, anti-icing systems for aircraft may be more costly than desired due to size, weight, complexity, and other factors that may be present with particular types of aircraft. Moreover, some anti-icing systems for aircraft may use more power than desired or may increase the temperature of the surface of the aircraft more than desired in various environmental conditions. Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues.